The present invention relates to an articulation arrangement for connecting individual elements of a folding structure and, more particularly, to an articulation arrangement for folding structures which consist of more than two individual elements and are configured to be unfolded and locked in an unfolded position and swivellably disposed on a central body. The arrangement comprises two hinge parts each rigidly fastened at one of two adjacent individual elements and swivellable about a common hinge axle, a slotted disk provided with a slot and forming part of one of the two hinge parts, a lever swivellably disposed on the other of the two hinge parts and provided with a pin which is configured and arranged such that, before the unfolded position is completely reached, the pin slides on an edge of the slotted disk and, in the completely unfolded position wherein locking occurs, the pin is engaged in the slot.
The present invention also relates to an articulation arrangement for a simplified folding structure which consists of only two individual elements and configured to be unfolded and locked in an unfolded condition and swivellably disposed on a central body, comprising two hinge parts which are each rigidly fastened on one of the two adjacent elements and swivellable about a common hinge axle, a slotted disk forming one of the two hinge parts, a lever swivellably disposed on the other of the two hinge parts and provided with a pin which is configured and arranged such that, before the unfolded condition is completely reached and the locking condition occur, the pin slides on an edge of the slotted disk and, in the completely unfolded locked condition, the pin is engaged in the slot.
One known articulation arrangement is shown in German Patent No. DE 32 15 434 C2 which describes a locking mechanism for unfoldable satellite solar generators. There, the folding structure is the solar generator which consists of individual panels constituting the individual elements. During the transport of the satellite into orbit, the solar generator is folded together and rests against the satellite which acts as the central body. After the removal of the satellite from the transport vehicle or after the final orbit is reached, the solar generator is unfolded, that is, brought into an elongated position, and is locked. For this purpose, the individual panels are connected with one another by articulation arrangements which permit the unfolding and subsequent locking in the unfolded condition. Each articulation arrangement is provided with two hinge parts which are each rigidly connected to one of the two adjacent panels or individual elements and can be swivelled about a common hinge axle. One of the two hinge parts has a slotted disk provided with a slot. On the other hinge part, a lever is rotatably disposed which is provided with a pin. During the folding operation, this pin slides on the edge of the slotted disk, and, after the conclusion of the unfolding operation, it will engage in its slot. A spring which exercises a tension between the hinge axle and the pin holds the pin in the slot in the locked condition.
A disadvantage of the known articulation arrangement is the fact that it is not constructed for permitting cancellation of the locked condition, i.e., an unlocking. However, such unlocking may be advantageous, particularly when satellites can be used several times or for testing operations on the ground, but also when it is desirable for carrying out maneuvers in the transfer path and/or the orbit or before changes of orbit to unlock and to fold the solar generator for a short time.
It is therefore an object of the present invention to provide an articulation arrangement which can be unlocked in a simple manner.
For folding structures with several individual elements or with only two individual elements, this is achieved by providing in the articulation arrangement a first pulley, arranged to be freely rotatably disposed on the one hinge part, a second pulley, arranged to be freely rotatably disposed on the other hinge part, a cam plate arranged to be freely rotatably disposed on the one hinge part and having an edge curve which changes continuously from a zone of minimal distance into a zone of maximal distance from an axis of rotation thereof, and which, in the unfolded position, rests with the zone of minimal distance against the engaged pin, and driving and transmitting means configured to effect simultaneous coordinated rotation of the first and second pulleys and of the cam plate, and to transmit the rotation to a pulley of an adjacent articulation arrangement or a pulley arranged to be freely rotatably disposed on one of the two hinge parts, a cam plate arranged to be freely rotatably disposed on one of the hinge parts and having an edge curve which changes continuously from a zone of minimal distance into a zone of maximal distance from an axis of rotation thereof, and which, in the locked condition, rests with the zone of minimal distance against the pin, and driving and transmitting means configured to effect simultaneous coordinated rotation of the pulley and of the cam plate.
In an embodiment of a folding structure with more than two individual elements, each articulation arrangement therefore has two respective freely rotatably disposed pulleys. The first of these pulleys is part of one and the second of the pulleys is part of the other of the two hinge parts of the articulation arrangement. In addition, a cam plate is disposed in a freely rotatable manner on one hinge part. The edge curve of this cam plate has a zone of minimal distance from its axis of rotation which changes continuously into a zone of maximal distance. In the fully unfolded and locked condition, the zone of minimal distance rests against the pin engaged in the slot of the slotted disk. Driving and transmission devices are provided which have the effect that, for the purpose of unlocking, the two pulleys and the cam plate of one articulation arrangement are set into a simultaneous and coordinated rotation, and which also have the effect that this rotation is transmitted to one of the pulleys of the next adjacent articulation arrangement. The rotation of the cam plate will now have the direct purpose of lifting the pin out of the slot of the slotted disk and thus releasing the locking. This unlocking will occur, at the latest, when the cam plate has rotated so far that its zone of maximal distance from the axis of rotation reaches the pin.
If there are only two individual elements of a folding structure, the articulation arrangement according to the present invention can be simplified considerably. The reason is that that pulley of the two pulleys may be omitted which, in the case of a folding structure comprising more than two individual elements, has the purpose of transmitting the rotation to one of the pulleys of the next adjacent articulation arrangement. The driving and transmitting devices which are required for this transmission will then also be omitted.